750/850 inquiry

[whiterabbitt]

so I found a local guy with a '80 up 850 engine and I was wondering, before I buy it, if I can use my 750 head on the 850 block. its the block that has the extra screw at the front of the cam chain tunnel. the reason I ask is that the 850 head requires the bs carbs which he doesnt have and the intake ports are shorter and dont have the sync ports in them.

thanks for letting me prey on your collective experience again

[TheCafeKid]

So you're wanting to put the 850 block in your 750 frame with the 750 top end??
Well, if that's the case, the 850 is a shaft drive engine so that wont work.
I dunno about using the 750 head on the 850 engine. It works the other way round and 79 850 heads were the same part number as the 750 head but they're different in 80. I'd imagine it could be done though. If the 80 850 head fits the 750 (which it does with some minor alteration to the cases from what I understand..) then one would think it works the other way round...

[tkent02]

The heads are the same except for the bigger intake ports and the extra valve cover bolt.

[whiterabbitt]

thanks tkent02
for clarification I intend to use the 850 cylinder block and pistons on my 750 bottom. I was just needing to know if I could use my 750 head on the later block that has the bolt in the front of the cam chain tunnel between the block and head with success.
I know the 850 is a shafty and have no desire to convert a perfectly good lightweight(relatively speaking) chain drive to shaft, that would just be silly.

so all I will need to make this work is an 850 head gasket and a new base gasket? minor case clearance taken into account.

[rwcfrank]

Whiterabbit, did you ever get this finished? How is it working out?

[whiterabbitt]

still collecting parts for this project, as I had a shock break recently and had to postpone getting gaskets and seals and such, in favor of some new progressives.
not to mention I am trying to figure out how to mount bst33ss carbs off a kat or bandit 600 to the 850 head.
and I dinged the pistons while pulling the 850 apart, corroded stud holes caught on the stud threads and the block fell back on the pistons . so I need another set of those.

all in all it may be a while before I get it all gathered and together. in the mean time I got a dyna s installed, new progressive shocks and springs to go on when the sleeves get here, and new chain and sprockets coming to go with the gs1100e swinger thats going on in the next couple of days.

no wonder my girls complain I never take them out, between the gs and gsxr, rent and such im flat broke ah well girls come and go, my bikes will never leave me